#include <stdio.h>
#include <stdbool.h>

void main(){
	//X座標
	int x = 0;
	int inputX = scanf("%d\n",&x);
	if(inputX == 2){
		printf("Xの入力ミス\n");
	}
	//Y座標
	int y = 0;
	int inputY = scanf("%d\n",&y);
	if(inputY == 2){
		printf("Yの入力ミス\n");
	}
	//移動距離
	int l = 0;
	int inputL = scanf("%d\n",&l);
	if(inputL == 2){
		printf("Lの入力ミス\n");
	}
	//命令回数
	int instructionCount = 0;
	//現在位置
	int trueX = 0 , trueY = 0;
	if( y < 0){
		instructionCount += 2;
		y *= -1;
	}else if(x != 0){
		instructionCount += 1;
	}

	while(x >= 0 || y >= 0){
		if(y >= 0){
			y -= l;
			instructionCount ++;
			continue;
		}
		if(x >= 0){
			x -= l;
			instructionCount ++;
			continue;
		}
	}
	printf("%d\n",instructionCount);
}